本文样式环境： win10 + vs2017 + c++11

算是踩坑吧，先前一直认为一块网卡只能有一个IP。 今天发现结构体中，定义了相关结构： 一块网卡可以用多个IP。

• 2.1 头文件

  #include
  #include

• 2.2 库

  Iphlpapi.lib

自己做了个封装，以后用，直接就它了。

• 3.1 头文件 源码

  #pragma once
  #include
  #include

  #if defined(_WIN32) || defined(_WIN64)
  #ifndef os_is_win
  #define os_is_win
  #endif // !os_is_win

  #elif defined(linux) || defined(linux) || defined(_unix) || defined(_unix) || defined(APPLE)
  #ifndef os_is_linux
  #define os_is_linux
  #endif // !os_is_linux

  #endif// ! defined(_WIN32) || defined(_WIN64)

  #if defined(os_is_win)

  #ifndef _net_api_export_
      #define _net_api_export_ __declspec(dllexport)
  #else
      #define _net_api_export_ __declspec(dllimport)
  #endif // !#ifndef  _net_api_export_

  #elif defined(os_is_linux)

  #ifndef _net_api_export_
      #define _net_api_export_  __attribute__((visibility ("default")))
  #endif // !_net_api_export_

  #endif //! defined(os_is_win)

  namespace lib_net
  {

  /**
  * @brief: ip information
  */
  struct ip_info_
  {
      std::string _inet4;
      std::string _inet6;
      std::string _subnet_mask;
      std::string _gate;
  void zero()
  {
      _inet4          = { "" };
      _inet6          = { "" };
      _subnet_mask    = { "" };
      _gate           = { "" };
  }
  
  ip_info_()
  {
      zero();
  }
  };
  
  using ip_info       = ip_info_;
  using ip_list       = std::list< ip_info>;
  
  /**
  * @brief: the information of adapter
  */
  struct net_adapter_info_
  {

  #ifdef os_is_win
  int _index;
  #endif //! os_is_win

      std::string _name;
      std::string _description;
      std::string _dev_type;
      std::string _mac;
  ip_list     _ip;
  int         _ip_size;
  
  void zero()
  {</code></pre>
  #ifdef os_is_win
  
              _index              = 0;
  
  #endif //! os_is_win
  
              _name               = { "" };
  
              _description        = { "" };
  
              _dev_type           = { "" };
  
              _mac                = { "" };
  
              _ip.clear();
  
              _ip_size            = 0;
  
          }
      net_adapter_info_()
      {
          zero();
      }
  };
  
  // to rename the type
  using net_ada_info = net_adapter_info_;
  
  // maybe, this machine has greater than 1 adapter
  using net_ada_list = std::list<net_ada_info>;
  //----------------------------------------------------------------------------------------
  /**
  * @brief: you could get the adapter information through this class on windows, linux and osx
  */
  class _net_api_export_ net_adapter_helper
  {
  public:
  //----------------------------------------------------------------------------------------
  static net_adapter_helper&amp; get_instance();
  
  /**
  * @brief: 获取Windows网卡信息
  */
  net_ada_list get_info_win();
  private:
      template<typename ... Args>
      static std::string str_format(const std::string &format, Args ... args)
      {
          auto size_buf = std::snprintf(nullptr, 0, format.c_str(), args ...) + 1;
          std::unique_ptr<char[]> buf(new(std::nothrow) char[size_buf]);
      if (!buf)
          return std::string("");
  
      std::snprintf(buf.get(), size_buf, format.c_str(), args ...);
  
      return std::string(buf.get(), buf.get() + size_buf - 1);
  }
  //----------------------------------------------------------------------------------------
      net_adapter_helper() = default;
      virtual ~net_adapter_helper() = default;
  net_adapter_helper(const net_adapter_helper&amp; instance) = delete;
  net_adapter_helper&amp; operator = (const net_adapter_helper&amp; instance) = delete;
  net_adapter_helper(const net_adapter_helper&amp;&amp; instance) = delete;
  net_adapter_helper&amp; operator = (const net_adapter_helper&amp;&amp; instance) = delete;
  };
  }

• 3.2 源文件源码

  #include "ip_helper.h"

  #include
  #include

  #if defined(os_is_win)
  #include
  #include
  #endif //! defined(os_is_win)

  namespace lib_net
  {

  /**
  *   @brief:
  */
  lib_net::net_adapter_helper& net_adapter_helper::get_instance()
  {
      static net_adapter_helper instance;
  return instance;
  }
  
  /**
  *   @brief:
  */
  lib_net::net_ada_list net_adapter_helper::get_info_win()
  {
      net_ada_list ret_list;
  std::unique_ptr< IP_ADAPTER_INFO> pai(new(std::nothrow) IP_ADAPTER_INFO);
  
  // 1. failed to apply space
  if (nullptr == pai || NULL == pai)
      return ret_list;
  
  // 2. to get the size of IP_ADAPTER_INFO structure
  unsigned long iai_size = sizeof(IP_ADAPTER_INFO);
  
  // 3.调用GetAdaptersInfo函数, 填充pIpAdapterInfo指针变量; 其中stSize参数既是一个输入量也是一个输出量
  int ret_val = GetAdaptersInfo(pai.get(), &iai_size);
  
  if (ERROR_BUFFER_OVERFLOW == ret_val)
  {
      pai.release();
  
      //重新申请内存空间用来存储所有网卡信息
      pai.reset((IP_ADAPTER_INFO*)(new(std::nothrow) char[iai_size]));
  
      if (nullptr == pai || NULL == pai)
      {
          return ret_list;
      }
  
      //再次调用GetAdaptersInfo函数,填充pIpAdapterInfo指针变量
      ret_val = GetAdaptersInfo(pai.get(), &iai_size);
  }
  
  if (ERROR_SUCCESS == ret_val)
  {
      // 3. to get information
      net_ada_info item;
      IP_ADAPTER_INFO *ppai = pai.get();
  
      while (ppai)
      {
          item._index         = ppai->Index;
          item._name          = std::string(ppai->AdapterName);
          item._description   = std::string(ppai->Description);
  
          // dev
          std::string str_type;
          switch (ppai->Type)
          {
          case MIB_IF_TYPE_OTHER:
              str_type = {"OTHER"};
              break;
  
          case MIB_IF_TYPE_ETHERNET:
              str_type = { "ETHERNET" };
              break;
  
          case MIB_IF_TYPE_TOKENRING:
              str_type = { "TOKENRING" };
              break;
  
          case MIB_IF_TYPE_FDDI:
              str_type = { "FDDI" };
              break;
  
          case MIB_IF_TYPE_PPP:
              str_type = { "PPP" };
              break;
  
          case MIB_IF_TYPE_LOOPBACK:
              str_type = { "LOOPBACK" };
              break;
  
          case MIB_IF_TYPE_SLIP:
              str_type = { "SLP" };
              break;
  
          default:
              str_type = { "" };
              break;
          }
  
          item._dev_type = str_type;
  
          // mac
          std::string str_mac;
          for (DWORD i = 0; i < ppai->AddressLength; i++)
          {
              if (i < ppai->AddressLength - 1)
                  str_mac += str_format("%02X-", ppai->Address[i]);
              else
                  str_mac += str_format("%02X", ppai->Address[i]);
          }
  
          item._mac = str_mac;
  
          // ip information
          ip_info ii_item;
          IP_ADDR_STRING *pial            = &(ppai->IpAddressList);
          int ip_size                     = 0;
          for (;;)
          {
              if (NULL != pial && nullptr != pial)
              {
                  ii_item._inet4          = std::string(pial->IpAddress.String);
                  ii_item._subnet_mask    = std::string(pial->IpMask.String);
                  ii_item._gate           = std::string(pai->GatewayList.IpAddress.String);
  
                  item._ip.push_back(ii_item);
                  pial                    = pial->Next;
                  ii_item.zero();
                  ip_size++;
              }
              else
              {
                  break;
              }
          } 
  
          item._ip_size   = ip_size;
          ret_list.push_back(item);
          item.zero();
  
          ppai = ppai->Next;
      } // end while
  }
  else
  {
      ;// error
  }
  
  return ret_list;
  }

  }

  net_ada_list nal = net_adapter_helper::get_instance().get_info_win();
  int list_size = nal.size();

  cout << "1.适配器数目 = " << list_size << "\n\n" << endl;

  #if defined(os_is_win)
  for (auto item : nal)
  {
  cout << "索引=" << item._index << endl;
  cout << "名字=" << item._name.c_str() << endl;
  cout << "描述=" << item._description.c_str() << endl;
  cout << "类型=" << item._dev_type.c_str() << endl;
  cout << "MAC=" << item._mac.c_str() << endl;

  int index = 0;
  cout << "ip有=" << item._ip_size << "个" << endl;
  for (auto item_ip : item._ip)
  {
      cout << "第" << ++index << "个ip" << endl;
      cout << "ipv4 = " << item_ip._inet4.c_str() << endl;
      cout << "子网掩码 = " << item_ip._subnet_mask.c_str() << endl;
      cout << "网关 = " << item_ip._gate.c_str() << endl;
      cout << "\n-------------------------";
  }
  
  cout << "\n--------------------------------------------------\n\n";

  }

  #endif //